Thomas will undergo surgery and is expected to be "100 percent" by training camp, according to the report.
The injury was originally sustained during the NFC Championship Game against the Green Bay Packers. It was previously reported that Thomas dislocated his shoulder but would play against the New England Patriots.
On Wednesday, the Seahawks announced that strong safety Kam Chancellor played the Super Bowl with a torn MCL. Cornerback Richard Sherman played with a left elbow injury, which he may need Tommy John surgery for.
Seattle lost the game 28-24.
- Molly Geary